JAUS Transport Considerations
|Publication Date:||1 September 2014|
This SAE Aerospace Information Report (AIR) discusses characteristics of data communications for the Joint Architecture for Unmanned Systems (JAUS). This document provides guidance on the aspects of transport media, unmanned systems and the characteristics of JAUS itself that are relevant to the definition of a JAUS transport specification.
The purpose of this document is to facilitate interoperation of unmanned vehicle systems, subsystems, and payloads by indicating relevant characteristics of transport media, unmanned systems and of JAUS itself, so that new transport standards may conform to expected performance.
JAUS Document Organization
The Joint Architecture for Unmanned Systems (JAUS) defines a suite of standards for use in the research, development, design, acquisition and deployment of Unmanned Systems. The JAUS Standards are divided into four essential scopes: the Domain Model, the Reference Architecture, the Transport Specification, and the Compliance Specification. Each scope is individually documented.
The Domain Model [JAUS-DM] is an abstract model of operational requirements that must be supported by a given unmanned system. This model is a tool to be used by a developer of an unmanned system to better understand the requirements of the acquirer of that unmanned system. The Domain Model is written in language understandable by both the developer and the acquirer. This line of documents is also known as the Architecture Framework for Unmanned Systems, or AFUS.
The Reference Architecture [JAUS-RA] is the technical specification used to implement unmanned systems in compliance with the JAUS standards and to assess technical compliance with the Standard. The most recent version of the Reference Architecture [JAUS-RA] is itself divided into three major sections: the Architecture Framework, the Message Definition, and the Message Set.
The Architecture Framework volume of the Reference Architecture provides a description of the structure of systems based on the Reference Architecture. This document serves as the primary mapping of Domain Model requirements to the JAUS message set.
The Message Definition volume of the Reference Architecture specifies the current JAUS message header and the types of messages employed. This document focuses on the rules of messaging as opposed to the domain-specific semantics contained in the message set.
The JAUS message header defined by this document is an application-layer header, and is specified without reference to any particular transport medium. JAUS Transport Standards note how implementations may make use of certain fields within this header to provide more efficient communications. However, transport implementations are not required to do so in order to maintain correctness or interoperability.
The Message Set volume of the Reference Architecture specifies the domain-specific messages and their exact content.
JAUS Transport defines communication services for JAUS messages. These services are the means by which messages are conveyed from one JAUS entity to another.
There are currently two documents relevant to the discussion of JAUS message transport: the JAUS Transport Considerations Report (this document) and the JAUS Transport Specification [JAUS-TS].
JAUS Transport Considerations Report
The JAUS Transport Considerations report (this document) discusses aspects of transport media, unmanned systems and widely used transport protocols, as well as characteristics of JAUS itself. This document then identifies characteristics of concern in the implementation of a compliant and efficient JAUS Transport standard. In this respect, this document serves as a meta-specification - in effect specifying the standards for a JAUS Transport standard.
This document may also be viewed as a summary of "lessons learned" by individuals involved in communications in unmanned systems. As the use of unmanned systems increases, this report will be updated and revised, as the experience of deploying more numerous, more autonomous unmanned systems increases.
JAUS Transport Specification
The JAUS Transport Specification [JAUS-TS] defines a family of transports for conveying JAUS messages between different JAUS entities via different link-layer implementation technologies. These transports are designed to incorporate the concerns outlined in the JAUS Transport Considerations Report.
The Compliance Specification [JAUS-CMP] defines compliance with JAUS. Since JAUS is a message-based architecture, compliance with JAUS is assessed by verifying that the message traffic between JAUS entities satisfies the definitions and requirements of the JAUS standards.
Field of Application
The Field of Application for the Transport Considerations report is data communications between nodes on a computer network.